One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,5,7,8)(13,21)(17,22)(18,23)(20,24)(27,33)(29,37)(31,35)(32,36)(1,2)(3,5)(4,6)(7,8)(9,10)(11,12)(13,17)(14,15)(16,19)(18,20)(21,22)(23,24)(25,26,30,28)(27,31,33,35)(29,32,37,36)(34,38,39,40)(1,3,4,7)(2,5,6,8)(10,15)(12,19)(17,22)(20,24)(25,27)(26,31)(28,35)(29,34)(30,33)(32,38)(36,40)(37,39)(9,11,14,16)(10,12,15,19)(13,18,21,23)(17,20,22,24)(25,28,30,26)(27,31,33,35)(29,36,37,32)(34,38,39,40)(9,12)(10,16)(11,15)(13,20)(14,19)(17,23)(18,22)(21,24)(25,29,30,37)(26,32,28,36)(27,34,33,39)(31,38,35,40)(9,13)(10,17)(11,18)(12,20)(14,21)(15,22)(16,23)(19,24) involution — undirectedA Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.